LONDON — The secret of "Pottermore" has been revealed: Harry Potter's wild wizard adventures are going digital.

Author J.K. Rowling announced Thursday that her seven Potter novels will be sold as e-books starting in October - ending the boy wizard's status as one of the highest-profile holdouts against digital publishing.

Rowling has written about 18,000 words of new material for the new site, www.pottermore.com, which promises to immerse users in her world of wizards, combining elements of computer games, social networking and an online store. She says the site includes "information I have been hoarding for years" about the books' characters and settings.

The project, unveiled at a London news conference, lets Potter fans delve into the world of Hogwarts School of Witchcraft and Wizardry. Sections let users shop for wands in Diagon Alley, travel to Hogwarts from the imaginary Platform 93/4 at London's King's Cross train station and be sorted into Hogwarts school houses by the perceptive Sorting Hat.

Along the way are wand fights, games and new information about characters known around the world, including Harry's reviled relatives, the Dursleys.

The site goes live July 31, when 1 million registered users will be chosen through an online competition to help flesh out the Pottermore world. It will be open to all users in October.

Initially, the site will follow the plotline of the first book, Harry Potter and the Sorcerer's Stone, with the six other adventures added later.

"(It's) a way I can be creative in a medium that didn't exist when I started the books back in 1990," Rowling said, adding it allowed her to incorporate the thousands of "stories, drawings, ideas, suggestions" she still receives from fans four years after the last Potter book was published.

Harry Potter fans who have been sharing their enthusiasm online for years should be delighted by the new digital world, but Rowling said she wanted to keep the emphasis of the site firmly on the written word.

"We've had a lot of requests for online games," she said. "I wanted to pull it back to reading."

The final book, Harry Potter and the Deathly Hallows, was published in 2007, and Rowling said she still has no plans to write an eighth. But she said Pottermore was a way to reconnect with a character and a universe she loved.

"It is exactly like an ex-boyfriend," Rowling said. "Finishing writing Harry - I have only ever cried in that way and that much when my mother died. I have never cried for a man the way I cried for Harry Potter."

Although she is bypassing established online retailers like Amazon, the creators of Pottermore say the books will be compatible with popular e-readers including Amazon's Kindle, Sony's Reader and Apple's iPad.

"It's very important to Jo to make the books available to everybody, not to make them available only to people who own a particular set of devices, or tethered to a particular set of platforms," said Tom Turcan, chief operating officer of the new venture, Pottermore Ltd.

He said prices for the e-books would be announced closer to October.

The website is a partnership with Sony Corp., and its online shop is described as "a potential outlet for Sony products." Rowling spokesman Mark Hutchinson said Sony was selected as "the most appropriate partner."

Booksellers who have sold millions of Potter books reacted strongly to the news they will be shut out of the electronic version. Jon Howells, spokesman for Britain's Waterstone's chain, said the Harry Potter book launches "have become the stuff of legend at Waterstone's and other booksellers."

"We're therefore disappointed that, having been a key factor in the growth of the Harry Potter phenomenon since the first book was published, the book trade is effectively banned from selling the long-awaited e-book editions," he said.

The Potter books have sold about 450 million copies worldwide and spawned a hit movie franchise and a theme park.

There may yet be another Potter book - a long-anticipated encyclopedia. Rowling said she was still considering compiling one.

"Will there ever be an encyclopedia?" Rowling said. "Possibly."

The final Harry Potter film, Harry Potter and the Deathly Hallows, Part 2, opens in the United States on July 15.